Side curtain airbag

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to International Application No. PCT/EP2007/010847, filed Dec. 12, 2007, which is based on and claims priority to German Patent Application No. 10 2006 061 968.4, filed Dec. 21, 2006.

FIELD OF THE INVENTION

The invention relates to a curtain airbag for a motor vehicle.

BACKGROUND OF THE INVENTION

A curtain airbag of the generic type is disclosed in DE 10 2005 011 676 A1. Such a curtain airbag is installed in the roof rail or frame area of a motor vehicle and serves to protect a vehicle occupant in case of a side impact or in case of a rollover. Such a curtain airbag has an airbag skin, which exhibits two side walls connected by means of an edge region, whereby the airbag skin encloses a gas chamber. This gas chamber is divided into at least one protective area (i.e., an inflatable area which serves for the protection of the occupants) which is positioned in such a way that a vehicle occupant can impact against it, and at least one guide chamber which is in fluid communication with the protective area. Such a guide chamber is located in the area of a pillar, in particular a B pillar or a C pillar, and in an installed state, the guide chamber prevents the curtain airbag from being caught in a hollow space (which is often present between the pillar trim and the vehicle side structure) during expansion of the protective area.

Retaining means such as mounting links or fixing lugs, which are located on the top edge of the airbag skin, serve to secure the curtain airbag in the roof rail area of the motor vehicle. Two variants are described in DE 10 2005 011 676 A1 with regard to the arrangement of such retaining means: in one variant, no mounting link is located on the guide chambers themselves, but only on the left and right of the respective guide chamber. In the other variant, a mounting link is located on the top edge of one of the guide chambers.

Both variants can be disadvantageous in some cases: if a fixing device is not directly assigned to a guide chamber, it cannot be ensured in all installation situations that the guide chamber positions itself as desired in the hollow space between the trim and the internal structure of the motor vehicle. If a fixing device in the form of a fixing lug or mounting link is located on the top edge of the guide chamber, installation is often difficult, particularly if the curtain airbag is fixed in the vehicle as described in DE 10 2005 011 676 A1, namely with the top edge downwards.

SUMMARY OF THE INVENTION

Accordingly, there is a need for a curtain airbag of the generic type which is easy to install and provides a high level of operational safety.

According to the present invention, a guide chamber fixing device is assigned to at least one guide chamber and is located at the height of the gas chamber. Thus, this guide chamber fixing device is not located in the edge region. As described below, there are basically two possibilities for forming the guide chamber fixing device.

In a first embodiment, the guide chamber fixing device exhibits a through-hole in each side wall, whereby these two through-holes lie above each other. In the installed state, a fixing element such as, but not limited to, a screw or a clip, for example, extends through the two through-holes through the airbag skin and through the guide chamber into the internal structure of the motor vehicle. In order to prevent gas leakage, a closed seam is preferably present, which surrounds the two through-holes and connects the two side walls.

In a second embodiment, a retaining device such as a lug is fixed (e.g., sewn or bonded) to the side wall pointing in the direction of the interior vehicle structure. The fixing point of this lug is at the height of the guide chamber and the end of the lug facing away from the fixing point may included a hole, through which a screw, a clip, or other similar fastening mechanism known in the art extends in the installed state.

Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates from the subsequent description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present invention will now be described in more detail below with reference to the following drawings.

<figref idrefs="DRAWINGS">FIG. 1</figref> is a plan view of a curtain airbag in its unfolded state,

<figref idrefs="DRAWINGS">FIG. 1</figref><i>a </i>is an exploded view of section D from <figref idrefs="DRAWINGS">FIG. 1</figref>,

<figref idrefs="DRAWINGS">FIG. 2</figref> shows the curtain airbag of <figref idrefs="DRAWINGS">FIG. 1</figref> in its rolled state as a package,

<figref idrefs="DRAWINGS">FIG. 3</figref> is a section view taken along Line A-A from <figref idrefs="DRAWINGS">FIG. 2</figref> in an installed state,

<figref idrefs="DRAWINGS">FIG. 4</figref> shows the curtain airbag of <figref idrefs="DRAWINGS">FIG. 3</figref> in its installed and expanded state,

<figref idrefs="DRAWINGS">FIG. 5</figref> shows a curtain airbag in its installed and expanded state according to a second embodiment of the invention,

<figref idrefs="DRAWINGS">FIG. 6</figref> shows an airbag unit with a rolled curtain airbag according to the second embodiment of the invention,

<figref idrefs="DRAWINGS">FIG. 7</figref> is a section view taken along Line B-B from <figref idrefs="DRAWINGS">FIG. 6</figref>, and

<figref idrefs="DRAWINGS">FIG. 8</figref> is view of <figref idrefs="DRAWINGS">FIG. 1</figref><i>a </i>according to an alternative embodiment of the invention showing the fixing between an additional fixing lug and an airbag skin.

DETAILED DESCRIPTION OF THE INVENTION

<figref idrefs="DRAWINGS">FIGS. 1 to 3</figref> show a curtain airbag unit embodying the principles of the present invention. The curtain airbag unit comprises a curtain airbag <b>10</b> and a gas generator <b>40</b>. According to a first embodiment, the gas generator is located at a side end of curtain airbag <b>10</b>. Curtain airbag <b>10</b> has an airbag skin <b>12</b>, which in turn exhibits two side walls <b>14</b>,<b>16</b> (see <figref idrefs="DRAWINGS">FIG. 3</figref>) connected with each other in an edge region <b>18</b> by means of a circumferential seam <b>20</b>. Airbag skin <b>12</b> surrounds a gas chamber <b>22</b>, which is divided into a protective area <b>22</b><i>a</i>, two guide chambers <b>22</b><i>b</i>, and a filling chamber <b>22</b><i>c</i>, whereby the filling chamber is located between protective area <b>22</b><i>a </i>and guide chambers <b>22</b><i>b</i>. In this embodiment, protective area <b>22</b><i>a </i>is divided into several chambers, <b>23</b><i>a</i>, <b>23</b><i>b</i>, <b>23</b><i>c</i>, <b>23</b><i>d</i>, and <b>23</b><i>e</i>. A first set of fixing devices in the form of fixing lugs <b>30</b> are located on an upper edge area <b>18</b><i>a</i>, wherein the fixing lugs <b>30</b> are configured to fix curtain airbag <b>10</b> to the internal structure of a motor vehicle.

A guide chamber fixing device is also assigned to each of the two guide chambers <b>22</b><i>b</i>. The construction of the guide chamber fixing devices will now be discussed in accordance with one aspect of the present invention. The two side walls <b>14</b>,<b>16</b> each exhibit a through-hole <b>24</b>, <b>26</b> in the area of guide chamber <b>22</b><i>b</i>, whereby these through-holes lie above each other. Circular sealing seam <b>27</b> extends around the two through-holes <b>24</b>, <b>26</b> (only shown in <figref idrefs="DRAWINGS">FIGS. 1</figref><i>a </i>and <b>3</b>). In the fastened state, as shown in <figref idrefs="DRAWINGS">FIG. 3</figref>, a fixing clip <b>28</b> such as a screw or the like extends through the two side walls <b>14</b>,<b>16</b>, and therefore also through guide chamber <b>22</b><i>b</i>, into a corresponding opening of an internal structure <b>50</b> of a vehicle.

As shown in <figref idrefs="DRAWINGS">FIG. 4</figref>, if gas chamber <b>22</b> is filled with gas, guide chamber <b>22</b><i>b </i>is divided into an upper section <b>22</b><i>b</i>′ and a lower section <b>22</b><i>b</i>″. Among other things, this has the consequence that the lower section, which is located between trim element <b>52</b> and internal vehicle structure <b>50</b>, is very precisely positioned, which leads to a desired level of high operational safety.

Filling of this lower section of the guide chamber occurs around seam <b>27</b>, as indicated in <figref idrefs="DRAWINGS">FIG. 1</figref>.

Installation is also very simple, as can be seen in <figref idrefs="DRAWINGS">FIG. 2</figref>, for example, as all fixing elements basically lie at uniform one height.

<figref idrefs="DRAWINGS">FIG. 5</figref> shows an alternative embodiment of the invention in a view corresponding to <figref idrefs="DRAWINGS">FIG. 4</figref>. Here, an additional fixing lug <b>32</b> serves as guide chamber fixing device, which is sewn together with side walls <b>14</b>,<b>16</b> on the side which faces towards the internal structure of the vehicle when it is in its installed state. This is achieved by means of a fixing or connecting seam <b>20</b><i>a</i>. Connecting seam <b>20</b><i>a </i>is located in the transitional area between guide chamber <b>22</b><i>b </i>and filling chamber <b>22</b><i>c</i>. The end of the additional fixing lug <b>32</b> facing away from connecting seam <b>20</b><i>a </i>exhibits a hole <b>34</b>, through which a clip <b>28</b> (or other fastening device known to those of ordinary skill in the art, such as, but not limited to a screw) also extends, so analogous to the previous embodiment, guide chamber <b>22</b><i>b </i>is very precisely positioned.

As can be seen from <figref idrefs="DRAWINGS">FIG. 8</figref>, connecting seam <b>20</b><i>a </i>is a section of circumferential seam <b>20</b>, which runs into the transitional area between guide chamber <b>22</b><i>b </i>and filling chamber <b>22</b><i>c</i>, and connects the two side walls with each other. Accordingly, the fixing seam <b>20</b><i>a </i>not only serves to fix the additional fixing lug <b>32</b>, but also serves as a division between guide chamber <b>22</b><i>b </i>and filling chamber <b>22</b><i>c </i>in some sections. Analogous to the first embodiment, this connection of the two side walls <b>14</b>,<b>16</b> in some sections improves the function of the guide chamber.

The foregoing embodiment with an additional lug for positioning the guide chamber is particularly preferred if the guide chamber—by means of one or several retaining tapes <b>36</b>, for example—is laid against the airbag rolled or folded into a package as can be seen in <figref idrefs="DRAWINGS">FIGS. 6 and 7</figref>, whereby the representation in <figref idrefs="DRAWINGS">FIG. 6</figref> corresponds to <figref idrefs="DRAWINGS">FIG. 2</figref> and <figref idrefs="DRAWINGS">FIG. 7</figref> is a section view taken along Line B-B in <figref idrefs="DRAWINGS">FIG. 6</figref>. The additional fixing lug can be directed upwards or downwards. Correspondingly, the fixing position of the additional fixing lugs on the internal structure of the vehicle would be located above or below protective area <b>22</b><i>a </i>rolled or folded together to form a package.

As can be seen from the Figures, the curtain airbag is arranged in the motor vehicle in such a way that its upper edge faces downwards. This arrangement is independent of whether the additional fixing lugs face upwards or downwards.

As a person skilled in the art will readily appreciate, the above description is meant as an illustration of the principles of this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation and change, without departing from spirit of this invention, as defined in the following claims.